Manufacture of grating



Oct. 16, 1934. J BATES 1,977,299

MANUFACTURE OF GRATING Fil ed Jan. 50, 1951 2 Sheets-Sheet 1 Oct. 16,1934. J BATES MANUFACTURE OF GRATING Patented Oct. 16, 1934 MANUFACTUREOF GRATING Albert J. Bates, Chicago, 111.

Application January 30, 1931, Serial No. 512,251

3 Claims.

The invention has reference to the manufacture of grating and itsprimary object is to provide an improved method of making grating.

In the drawings which accompany and form a part of this specification ordisclosure and in which like numerals of reference denote correspondingparts throughout the several views:

Fig. 1 .is a perspective of a grating made in accordance with thepresent method;

Fig. 2 is a perspective, illustrating the manner in which the tie barsof the grating are threaded or inserted through the slots in the masterbars, before they are operated upon to develop their lockingproclivities;

Fig. 3 is a cross section of one of the tie bars taken midway betweentwo of the master bars and showing the central part of the tie barportion between the two master bars after bending thereof into itsvertical or right angle position and the ends of said portion turnedupwards and downwards and shaped to form shoulders which abut directlyagainst the sides of the master bars and prevent the master bars fromrolling relatively to the tie bars;

Fig. Bais a cross section of one of the tie bars taken approximatelyone-sixteenth of an inch from one of the master bars and illustratingthe construction and arrangement of the shoul ders;

Fig. 3b is a section taken on the line 3 -3 of Fig. 3;

Fig. 4 is a view, partly in section and partly in side elevation,showing the dies which serve to bend or twistat right angles theportions of the tie bars between the master bars and to form theshoulders at the ends of the twisted portions, before shift thereof toeffect the bending and shearing of the tie bars, and also showing thedies which engage and hold the end parts of the portions of the tie barsbetween the master bars during operation of the bending and shearingdies;

Fig. 5 is a view, showing the bending and shearing dies after they havebeen advanced or shifted sufiiciently to effect a preliminary twistingof the tie bars and bring the cutting parts into a position wherein theyengage the edges of the tie bars and are in readiness to coact with thesides of the master bars and effect shearing for the purpose of formingthe shoulders;

Fig. 6 is a view, showing the bending and shearing dies after they havebeen advanced or shifted to effect a complete bending or twisting of thetie bars and to form shoulders at the ends of the twisted tie barportions which serve rigidly to lock the master bars in place;

Fig. '7 is a vertical transverse sectional view taken on the line '7-7of Fig. 4 and illustrating in detail the construction of the holdingdies and the manner in which such dies operate to prevent distortion ofthe master and tie bars during the bending and shearing operation;

Fig. 8 is a horizontal section taken on the line 8-8 of Fig. 4 andillustrating the cross sectional construction of the dies;

Fig. 9 is a. perspective of one of the combined bending and shearingdies; and

Fig. 10 is a perspective, showing the bending and shearing dies beforethe twisting and shearing of the tie bars.

The method which forms the subject matter of the invention contemplatesthe fabrication or manufacture of a grating which comprises a series ofmaster bars 11 and a series of transversely extending tie bars 12. Themaster bars are formed of any suitable metal, such as steel, and are ofsubstantially uniform height and thickness. They are arranged insideby-side and parallel relation and so that the upper edges thereofare in alignment and are spaced equal distances apart as illustrated inFig. 1. The tie bars 12 are formed of strips of steel and arerectangular in cross section. They serve to hold the master bars 11 inconnected relation and extend through groups or sets of aligned slots 13in the master bars. The slots 13 conform to the cross sectional shape ofthe tie bars and extend longitudinally with respect to the master bars.In fabricating the grating, the tie bars 12 are first threaded orinserted through the slots 13 as illustrated in Fig. 2. Thereafter, theportions of the bars between the master bars undergo reformation ashereinafter described, so that the central parts thereof, that is, theparts midway between the master bars, extend substantially at rightangles or perpendicularly with respect to the portions within the slots.The portions of the tie bars between the master bars comprise upperparts 14 and. lower parts 15. The upper parts are curved in onedirection and the lower parts are curved in the opposite direction. As aresult of this arrangement, the grating as a whole is of an ornamentalcharacter and is exceedingly attractive and pleasing to the eye. Inaddition to the upper and lower parts 14 and 15, the portions of the tiebars between the master bars comprise connecting parts 16, uppershoulders 1'7 and lower shoulders 18. The connecting parts 16 are 10-cated at the ends of the portions of the tie bars and serve to connectsuch portions to the portions of the tie bars within the slots 13. Asclearly illustrated in Fig. 3a. of the drawings, the parts 16 are notprocessed in any way and extend Horizontally. The portions of the tiebars within the slots 13 of the master bars completely fill theaforesaid slots and hence serve to prevent displacement of the tie barslongitudinally with respect to the master bars. The

upper shoulders 17 are located at the ends of the upper parts 14 of thetie bars and are disconnected with respect to the contiguous end partsof the portions of the tie bars within the slots 13. Inasmuch as theyare formed as hereinafter described, by shearing the edges of the tiebars against the master bars, they extend substantially at right anglesto the aforesaid portions of the tie bars within the slots in the masterbars and abut directly against the sides of the master bars in order torender the grating rigid and prevent the master bars from rolling orshifting laterally one relatively to the others. The lower shoulders 18are located at the ends of the lower parts 15 and abut against the sidesof the master bars so as to assist the shoulders 17 in preventing rollof the master bars. They are disconnected with respect to the contiguousends of the portions of the tie bars within the slots 13 and extenddownwardly at substantially right angles to such portions of the tiebars. A distinctive and novel feature of the invention resides in thefact that the shoulders 17 and 18 are formed by shearing the edges ofthe tie bars after the tie bars have been threaded or inserted throughthe slots in the master bar. The shearing .is accomplished by dies whichare described hereafter and cooperate with the master bars to effect aninward shearing of the edges of the tie bars ad jacent the master barsand are so formed that the shoulders are bent perpendicularly withrespect to the tie bar portions within the slots and engage frictionallythe sides of the master bars. By utilizing the shoulders 17 and 18 atthe ends of the twisted or bent portions of the tie bars between themaster bars, the master bars are rigidly held in connected relation. Inaddition, the grating as a whole is strengthened and made extremelyrigid. This is attributable to the fact that the shoulders 17 and 18which abut directly against the sides of the master bars prevent bendingof the tie bars when weight is applied to the grating. By virtue of thefact that the portions of the tie bars between the master bars aretwisted or bent into place and the upper and lower parts 17 and 18 arecurved as a result of the bending operation, the shoulders 17 are offsetwith respect to the shoulders 18 and are positioned at one side of thecentral part of the twisted tie bar portions. The slots 13 arepreferably arranged so that the upper parts 14 of the tie bars are flushwith the top or upper edges of the master bars.

To prevent peoples feet from skidding or slipping on the grating, thesides of the master bars are indented, as at 19, in order to force themetal upwardly and form projections 20 at the top or upper edges of themaster bars. These projections are arranged in pairs and are preferablypositioned between the tie bars 12. They embody comparatively sharpedges 21 above the top edges of the master bars and tend to present arufiened surface at the top of the grating which eifectively precludesslippage or skidding.

Twisting or bending of the portions of the tie bars between the masterbars is effected by means of sets of dies. Each of these sets consistsof an upper combined bending and shearing die 22, a lower combinedbending and shearing die 23, an upper holding die 24 and a lower holdingdie 25. By way of a preliminary explanation, the various dies areassociated with a power-operated machine (not shown) which is designedfor volume production and consists of an upper vertically reciprocatinghead for the dies 22 and a-lower vertically reciprocating head for thedies 23. .The two heads are reciprocated to and from each other and areso arranged and timed that the dies of the heads are brought intosubstantial registry (see Fig. 6). The dies '22 and 23 operate duringmovement of the heads towards each other, to engage opposite edges ofthe tie bars and are so constructed and shaped that they shear and bendthe v portions of the tie bars between the master bars into the designor shape heretofore described.

The upper combined bending and shearing dies 22 are arranged in rows andare held in spaced relation by metallic plates or strips 26. The latter,together with the upper combined bending and shearing dies 22 aremounted in the upper die-carrying head of the machine and arereciprocated vertically. The grating is held in a suitable retainer (notshown) beneath the upper head and above the lower head, after it hasbeen assembled in a preliminary manner by inserting the tie bars 12through the elongated slots 13 in the master bars. The combined bendingand shearing dies 22 are adapted to be shifted downwardly between themaster bars in order to effect downward deflection or bending of the tiebars 12. Each of the upper combined bending and shearing dies 22 isformed of a single block of metal and consists of a bender 27and a pairof shearers 28. The shearers are located at the sides of the bender 27and operate as hereinafter described to shear the ends of the subjacenttie bar portions in order to form the lower shoulders 18. The bender 27consists of a vertically extending upper part 27 and a lower part 27'The latter extends downwardly and outwardly with respect to the upperpart 27, is convex and serves, during downward movement of the die 22,to bend or deflect downwardly the subjacent tie bar portion so as toform the lower part 15 of such portion. The upper part 27 of the bender27 is convex and operates toward the end of the downward stroke of thedie 22 to swing the subjacent tie bar portion into a position. whereinit is disposed at substantially right angles with respect to the tie barportions within the slots 13. During the initial part of the downwardstroke of the die 22, the lower part 27 of the bender engages thesubjacent tie bar portion in the manner illustrated in Fig. 4. As thedie is shifted downwardly from the position illustrated in Fig. 4, thelower part 27 of the bender 27 engages slidably the contiguous part ofthe subjacent tie bar portion and deflects it downwardly in the mannerillustrated in Fig. 5. As the die 22 approaches the end of its downwardstroke, the upper part 27 of the bender is brought into contact with thebent or deflected part of the subjacent tie bar portion and serves tobend or deflect the latter into a right angle P 11 101; as llustrated inFig. 6. The shearers- 28 at the sides of the bender 27 are provided atthe lower ends thereof with shearing edges 28. The latter are inclineddownwardly and outwardly and are located adjacent to and outwardly ofthe lower part 2'7 of the bender 27. During downward movement of the die22, the shearing edges 28 of the shearers 28 slide against thecontiguous faces of the master bars 11 and sever the ends of thesubjacent tie bar portion from the tie bar portions within the slots 13to form the shoulders 18 at the ends of the lower part 15. In additionto the shearing edges 28, the shearers 28 are provided with verticallyextending edges 28 The latter are located at the sides of the upper part27 of the bender and operate, as illustrated in Figure 6, to bend theshoulders 18 into their right angle position. The lower ends of theedges 28 terminate adjacent the lower end of the upper part 27* of thebender 27. The lower ends of the shearers 28 are tapered, as at 29, soas to facilitate passage of the die 22 between the master bars. Duringdownward movement of the die 22, the lower part 2'7 of the bender 27, aspreviously pointed out, deflects downwardly the contiguous part of thesubjacent tie bar portion. After a partial bending or deflection, theshearing edges 28* of the shearers cut or shear the contiguous end partsof the subjacent tie bar portion so as to form the lower shoulders 18.As the die 22 reaches the end of its downward stroke, the upper part 2'!of the bender and the edges 23 of the shearers effect completedeflection of the subjacent tie bar part and bring the lower shoulders18, as illustrated in Fig. 6, into the right angle position. By virtueof the fact that the shearers- 28 engage slidably the master bars andthe shearing is accomplished with the aid of the master bars, theshoulders 18 abut directly against the sdes of the master bars and thus,after deflection thereof into place, effectively hold the master barsagainst rolling. Inasmuch as the parts 2'7 and 2'7 of the bender areconvex, the lower part 18 of the subjacent tie bar portion is curved.

The lower combined bending and sharing dies 23 are arranged in rows andare held in spaced relation similarly to the upper dies 22. They areoffset with respect to the upper dies 22 and are mounted in the lowerhead of the machine. Upward bending of the portions of the tie barsbetween the master bars is accomplished by the dies 23. The latter aresimilar in construction to the dies 22. Each of the lower combinedbending and shearing dies 23 comprises a bender 30 and a pair ofshearers 31. The bender comprises a vertically extending lower part 30and an upper part 30. The latter is inclined upwardly and outwardly andoperates, during upward movement to bend and deflect upwardly thecontiguous part of the subjacent tie bar portion. The lower part 30 ofthe bender 30 engages the tie bar portion after the upper part 30 andcompletes the deflection so as to form the upper part 14. The twoshearers 31 are located at opposite sides of the bender 30 and embodyshearing edges 31 and vertically extending edges 31". The shearing edgesoperate, during upward movement of the die 23, to shear the contiguousend parts of the subjacent tie bar portion to form the shoulders 1'7.The edges 31*, after formation of the shoulders 1'? by the shearingedges 31 engage the shoulders and shift them upwardly so that theyextend at right angles to the tie bar portions within the slots 13. Theupper ends of the shearers 31 are tapered as at 32 so as to facilitatepassage of the lower die between the master bars. The parts 30 and 30 ofthe bender are convex.

The upper holding dies 24 are associated with the upper combined bendingand shearing dies 22 and are arranged in rows. They are positionedadjacent the benders 27, are shifted downwardly into their operativeposition before shift of the upper combined bending and shearing dies 22and serve to prevent rupture or tearing of the metal during operation ofsaid dies 22. Each of the holding dies 24 is formed of a single strip orplate of metal and is provided at one side thereof with a lug orprojection 33. The latter projects laterally and is adapted to lap andabut against the upper edge of the subjacent master bar so as to preventrupture of the metal when the lower combined bending and shearing dies23 are shifted upwardly to bend or deflect upwardly the parts of the tiebar portions which form the upper parts 14. The lower ends of the upperholding dies 24 fit between the master bars and are adapted to abutdirectly against the upper faces of the tie bars as illustrated in Figs.4, 'l and 10. Semicircular openings 34 are formed in the lower ends ofthe dies 24 so as to accomodate the upper parts 14 of the portions ofthe tie bars between the master bars when such parts are shiftedupwardly into their right angle position by the lower combined bendingand shearing dies 23. The faces of the dies 24 that are opposite to thebenders 27 of the upper combined bending and shearing dies 22 aregrooved longitudinally as at 35 in order to accomodate the aforesaidbenders. The opposite faces of the holding dies 24 have cut awayportions 36 and recesses 37. The cutaway portions 36 are positionedadjacent the openings 34 and receive the upper shoulders 17 when thelatter are shifted upwardly into a vertical position by the action ofthe edges 31 of the shearers of the dies 23. The recesses 37 conform tothe curvature of the benders of the lower combined bending and shearingdies and receive the lower parts 30 of said benders at the end of theupward stroke of the dies 23.

The lower holding dies 25 are associated with the lower combined bendingand shearing dies 23 and are similar in construction to the upperholding dies 24. They are formed of metallic strips or plates and areprovided at the sides thereof with lateral projections or lugs 38. Thelatter are adapted to engage the lower edges of the master bars of thegrating and cooperate with the projections 33 of the upper holdingmembers 24 to hold the master bars in place during shift of the dies 22and 23. The upper ends of the lower holding dies fit between the masterbars and engage the lower faces of the tie bars as illustrated in Figs.4 and 7. In order to accommodate the lower parts 15 of the portions ofthe tie bars between the master bars when such parts are deflected bythe benders of the upper dies 22, openings 39 are formed in the upperends of the lower holding dies. These openings, like the openings 34 ofthe upper holding dies, are semicircular in conformation. The faces ofthe lower holding dies that are opposite to the dies 23 are groovedlongitudinally as at 40 so as to receive slidably the lower part 30 ofthe benders 30. The opposed faces of the lower holding dies are providedwith cut away portions 41 and recesses 42. The cut away portions, asindicated in Fig. 6, are located at opposite sides of the openings 39and receive the shoulders 18 when the latter are shifted downwardly bythe edges 28 of the shearers 28. The recesses 42 receive the upperportions 27 of the benders 27 when the upper combined bending andshearing dies reach the end of their downward stroke. The lower holdingdies 25 are slidable relatively bending and shearing dies 23 and areadapted to be shifted into their operative position before shift of thedies 23 to efiect upward bending or deflection of the portions of thetie bars between the master bars.

In bending or deflecting the portions of the tie bars between the masterbars, the upper and lower holding dies are first shifted into theiroperative position. The upper and lower dies 22 and 23 are then shiftedtowards each other so as to effect the desired bending of the tie barportions between the master bars and form the shoulders 17 and 18 whichabut directly against the sides of the master bars and serve, as

previously pointed out, to prevent rolling of the master bars onerelatively to the others. During the downward stroke of the uppercombined bending and shearing dies 22, the contiguous parts of the tiebar portions between the master bars are deflected downwardly into theopenings 39 of the lower holding dies and at thesame time, the end partsare sheared from the contiguous parts of the tie bar portions within theslots 13 so as to form the shoulders 18. During upstroke of the lowercombined bending and shearing dies, the opposite parts of the tie barportions between the master bars are deflected upwardly into theopenings 36 of the upper holding dies and at the same time, theshoulders 17 are formed. Upon release of the dies 22, 23, 24 and 25, thegrating is ready for use.

The invention is not to be understood as restricted to the details setforth, since these may be modified within the scope of the appended tothe lower combined claims, without departing from the spirit and scopeof the invention.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1. That improvement in the manufacture of grating which consists infirst inserting tie bars .through sets of aligned slots in a group oflat erally spaced master bars, and then shearing the ends of theportions of the tie bars between the master bars inwardly from the sideedges and against the sides of the master bars and bending or deflectingthem to form shoulders that lap the side faces of the master bars andhold the master bars against displacement relatively to the tie bars.

2. That improvement in the manufacture of grating which consists infirst inserting tie bars through sets of aligned slots in a group oflaterally spaced master bars, and then shearing the ends of the portionsof the tie bars between the master bars inwardly from the side edges andagainst the side faces of the master bars and bending them in oppositedirections to form pairs of oppositely extending shoulders that lap theside faces of the master bars and hold the master bars againstdisplacement relatively to the tie bars.

3. That improvement in the manufacture of grating which consists infirst inserting tie bars through sets of aligned slots in a group oflaterally spaced master bars, and then deflecting the central parts ofthe portions of the tie bars between the master bars into an angularposition with respect to the portions of the tie bars within the slotsof the master bars and simultaneously shearing the ends -of said firstmentioned portions inwardly from the side edges and against the sidefaces of the master bars and bending or deflecting them adjacent thesheared parts in opposite directions to form shoulders that lap the sidefaces of the master bars and hold the master bars against displacementrelatively to the tie bars.

ALBERT J. BATES.

